Moussa Rassaei, Mehdi Derakhshannia and Bahar Rahbar
Abstract
The existence of viscous flow behind dams leads to accumulation of sediments and, therefore, areduction in the dams performance. One method of reducing the symptomatic damages due to viscous flow is barrier placement in the dams upstream. In this study a physical model was constructed in order to investigate viscous flow. To do so, a number of cylindrical obstacles were placed in the flow path, and then the changes in velocity and volumetric flow rate were calculated, both with and without obstacles, and the results were compared. Changes in the slope of Flume floor with volumetric flow rate, according toviscosity, were also examined. The results showed that changes in slope, volumetric flow rate, and viscosity do not create any changes in the velocity and the intensity of volumetric flow rate because of the obstacle density is too high and neutralizes every effect of these parameters. However, furthermore, the arrangement of obstacles in this study caused a 50 to 70 percent decrease in velocity and volumetric flow rate of viscous flow.